Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Front Pharmacol ; 13: 815742, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35295322

RESUMEN

Traditionally the role of phytochemistry in the ethnopharmacology of North and Central America has been to characterize plant materials so that they can be produced reproducibly for commercial use or to identify active principles in unstudied traditional medicines for drug discovery. With new decolonial objectives coming from Indigenous communities, emphasis has shifted to evaluating the safety and efficacy of traditional medicines and preparations for community use. With new techniques and technologies available, scientific focus has shifted from individual bioactives to more rapid and comprehensive chemical characterizations and polypharmacy of traditional medicines. Untargeted metabolomics and associated statistical treatments have greatly expanded identification of components, improved species and cultivar identification and provided means for identifying multiple activity biomarkers, via chemometric and biochemometric analysis. New integrated techniques are available for identifying multiple active principles and synergists. The recent explosion of information is not without problems that need to be addressed including many unconfirmed tentative identifications of phytochemicals, lack of quantitative testing, superficial chemical activity testing and continuing need for dereplication.

2.
Front Pharmacol ; 12: 511078, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35126097

RESUMEN

An ethnopharmacological metanalysis was conducted with a large database available on antidiabetic activities of plant foods and medicines from the northern boreal forest, which are traditionally used by the indigenous Cree of James Bay, Quebec, Canada. The objective was to determine which bioassays are closely associated with the traditional knowledge of the Cree and which pharmacological metrics and phytochemical signals best define these plants and their groups. Data from 17 plant species, ethnobotanically ranked by syndromic importance value for treatment of 15 diabetic symptoms, was used along with 49 bioassay endpoints reported across numerous pharmacological studies and a metabolomics dataset. Standardized activities were separated into primary, secondary and safety categories and summed to produce a Pharmacological Importance Value (PIV) in each of the three categories for each species. To address the question of which pharmacological metrics and phytochemical signals best define the CEI anti-diabetes plants, multivariate analyses were undertaken to determine groupings of plant families and plant parts. The analysis identified Larix larcina as the highest PIV species in primary assays, Salix planifolia in secondary assays, and Kalmia angustifolia in safety assays, as well as a ranking of other less active species by PIV. Multivariate analysis showed that activity in safety PIV monitored mainly with cytochrome P450 inhibition patterns best reflected patterns of traditional medicine importance in Cree traditional knowledge, whereas potent primary bioactivities were seen in individual plants determined to be most important to the Cree for anti-diabetes purposes. In the secondary anti-diabetes assays, pharmacological variability was better described by plant biology, mostly in terms of the plant part used. Key signal in the metabolomics loadings plots for activity were phenolics especially quercetin derivatives. Traditional Indigenous knowledge in this analysis was shown to be able to guide the identification of plant pharmacological qualities in scientific terms.

3.
Planta Med ; 87(4): 294-304, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33296937

RESUMEN

Recent research demonstrates that Echinacea possesses cannabimimetic activity with potential applications beyond common contemporary uses for relief of cold and flu symptoms. In this study, we investigated the in vitro inhibitory effect of root extracts of Echinacea purpurea and Echinacea angustifolia on fatty acid amide hydrolase, the main enzyme that degrades the endocannabinoid anandamide. The objective was to relate variation in bioactivity between commercial Echinacea genotypes to their phytochemical profiles and to identify determinants of activity using biochemometric analysis. Forty root extracts of each of species were tested for inhibition of fatty acid amide hydrolase and analyzed by HPLC-DAD/MS to identify and quantitate alkylamides and caffeic acid derivatives. Fatty acid amide hydrolase inhibition ranged from 34 - 80% among E. angustifolia genotypes and from 33 - 87% among E. purpurea genotypes. Simple linear regression revealed the caffeic acid derivatives caftaric acid and cichoric acid, and the alkylamide dodeca-2E,4Z-diene-8,10-diynioc acid 2-methylbutylamide, as the strongest determinants of inhibition in E. purpurea (r* = 0.53, 0.45, and 0.20, respectively) while in E. angustifolia, only CADs were significantly associated with activity, most notably echinacoside (r* = 0.26). Regression analysis using compound groups generated by hierarchical clustering similarly indicated that caffeic acid derivatives contributed more than alkylamides to in vitro activity. Testing pure compounds identified as determinants of activity revealed cichoric acid (IC50 = 45 ± 4 µM) and dodeca-2E,4E,8Z,10E-tetraenoic acid isobutylamide (IC50 = 54 ± 2 µM) as the most active. The results suggest that several phytochemicals may contribute to Echinacea's cannabimimetic activity and that ample variation in genotypes exists for selection of high-activity germplasm in breeding programs.


Asunto(s)
Echinacea , Amidohidrolasas/genética , Cromatografía Líquida de Alta Presión , Extractos Vegetales/farmacología
4.
J Child Adolesc Psychopharmacol ; 30(1): 38-47, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31670573

RESUMEN

Background: Some pediatric patients with attention-deficit/hyperactivity disorder (ADHD) use natural health products (NHPs) such as herbal remedies. Although herbal remedies are generally considered to be safe when they are used appropriately, they may contain active components that can interact with medications being used concurrently, with potential for NHP-drug interactions leading to adverse events. Objectives: The objectives of this study were (1) to identify adverse event reports (AERs) involving commonly used herbal remedies and ADHD prescription medicines in children and adolescents; (2) to evaluate the quality of collected AERs; and (3) to assess whether NHP-drug interactions can be causally linked to reported adverse events. Methods: We systematically searched the FDAble database (FDAble.com) for herbal remedies commonly used by patients (4-18 years old) also taking ADHD drugs from 1997 to 2015. We assessed the completeness of the AERs and used three causality assessment tools modified for NHPs (Naranjo Adverse Drug Reaction Probability Scale, HORN Drug Interaction Probability Scale, and World Health Organization Uppsala Monitoring Centre Scale). Results: Of the 23 identified AERs involving both an herbal remedy and an ADHD prescription medication, most involved multiple (>3) substances with inadequate detail to assess multiple potential interactions. Following data extraction and evaluation of completeness, five AERs involving only one herbal remedy and one ADHD medication were evaluated for causality. An NHP-drug interaction was assessed to be probable in one case and to be possible in another. Both these reports involved a methylphenidate formulation and St. John's wort. Conclusions: Eighteen of the 23 identified AERs involving both an herbal remedy and an ADHD drug also involved other multiple ingredient products. The reporting quality was poor for the five AERs examined. Further research is needed to study the interaction between St. John's wort and methylphenidate.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Interacciones de Hierba-Droga , Hypericum/efectos adversos , Metilfenidato/efectos adversos , Preparaciones de Plantas/efectos adversos , Adolescente , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Estimulantes del Sistema Nervioso Central/efectos adversos , Estimulantes del Sistema Nervioso Central/uso terapéutico , Niño , Preescolar , Humanos , Metilfenidato/uso terapéutico , Preparaciones de Plantas/uso terapéutico , Estados Unidos/epidemiología
5.
ACS Sens ; 4(10): 2706-2715, 2019 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-31453690

RESUMEN

Quality control is imperative for Cannabis since the primary cannabinoids, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), elicit very different pharmacological effects. THC/CBD ratios are currently determined by techniques not readily accessible by consumers or dispensaries and which are impractical for use in the field by law-enforcement agencies. CuPc- and F16-CuPc-based organic thin-film transistors have been combined with a cannabinoid-sensitive chromophore for the detection and differentiation of THC and CBD. The combined use of these well-characterized and inexpensive p- and n-type materials afforded the determination of the CBD/THC ratio from rapid plant extracts, with results indistinguishable from high-pressure liquid chromatography. Analysis of the prepyrolyzed sample accurately predicted postpyrolysis THC/CBD, which ultimately influences the psychotropic and medicinal effects of the specific plant. The devices were also capable of vapor-phase sensing, producing a unique electrical output for THC and CBD relative to other potentially interfering vaporized organic products. The analysis of complex medicinal plant extracts and vapors, normally reserved for advanced analytical infrastructure, can be achieved with ease, at low cost, and on the spot, using organic thin-film transistors.


Asunto(s)
Cannabidiol/análisis , Dronabinol/análisis , Cannabidiol/química , Cobre/química , Dronabinol/química , Indoles/química , Compuestos Organometálicos/química , Extractos Vegetales/química , Silanos/química , Transistores Electrónicos , Volatilización
6.
BMC Complement Altern Med ; 19(1): 137, 2019 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-31215420

RESUMEN

BACKGROUND: The Cree of Eeyou Istchee (James Bay area of northern Quebec) suffer from a high rate of diabetes and its complications partly due to the introduction of the western lifestyle within their culture. As part of a search for alternative medicine based on traditional practice, this project evaluates the biological activity of Picea mariana (Mill.) Britton, Sterns & Poggenb. needle, bark, and cone, in preventing glucose toxicity to PC12-AC cells in vitro (a diabetic neurophathy model) and whether habitat and growth environment influence this activity. METHODS: Three different organs (needle, bark, and cone) of P. mariana were collected at different geographical locations and ecological conditions and their 80% ethanolic extracts were prepared. Extracts were then tested for their ability to protect PC12-AC cells from hyperglycaemic challenge at physiologically relevant concentrations of 0.25, 0.5, 1.0 and 2.0 µg/mL. Folin-Ciocalteu method was used to determine the total phenolic content of P. mariana extracts. RESULTS: All extracts were well-tolerated in vitro exhibiting LD50 of 25 µg/mL or higher. Extracts from all tested organs showed a cytoprotective concentration-dependent response. Furthermore, the cytoprotective activity was habitat- and growth environment-dependent with plants grown in bog or forest habitats in coastal or inland environments exhibiting different cytoprotective efficacies. These differences in activity correlated with total phenolic content but not with antioxidant activity. In addition, this paper provides the first complete Ultra-Performance Liquid Chromatography-quadrupole time-of-flight (UPLC-QTOF) mass spectrometry analysis of Picea mariana's bark, needles and cones. CONCLUSIONS: Together, these results provide further understanding of the cytoprotective activity of Canadian boreal forest plants identified by the Cree healers of Eeyou Istchee in a cell model of diabetic neuropathy. Their activity is relevant to diabetic peripheral neuropathic complications and shows that their properties can be optimized by harvesting in optimal growth environments.


Asunto(s)
Diabetes Mellitus/fisiopatología , Glucosa/toxicidad , Hipoglucemiantes/farmacología , Picea/química , Extractos Vegetales/farmacología , Sustancias Protectoras/farmacología , Animales , Supervivencia Celular/efectos de los fármacos , Diabetes Mellitus/tratamiento farmacológico , Diabetes Mellitus/metabolismo , Glucosa/metabolismo , Hipoglucemiantes/análisis , Células PC12 , Extractos Vegetales/análisis , Sustancias Protectoras/análisis , Quebec , Ratas
7.
J Pharm Pharmacol ; 71(3): 429-437, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30467864

RESUMEN

OBJECTIVES: A novel anxiolytic natural health product (NHP) containing Souroubea sympetala and Platanus occidentalis is available for the companion animal market and is currently being developed for clinical evaluation. Addressing the risk of potential NHP-drug interactions, this study investigated S. sympetala and P. occidentalis plant extracts, and their identified bioactive compounds, for effects on the activity of cytochrome P450 (CYP) isozymes and the metabolism of the conventional anti-anxiety medication diazepam. METHODS: Souroubea sympetala and P. occidentalis extracts, a 1 : 1 blend of the two extracts, and five triterpenes were tested for inhibitory effects on human recombinant CYP3A4, CYP2D6, CYP2C9 and CYP2C19 activity using a fluorometric plate assay. Direct effects on the metabolism of diazepam were evaluated using human liver microsomes with drug and metabolite quantification by ultra-high-pressure liquid chromatography and mass spectroscopy. KEY FINDINGS: The active substances betulinic acid (BA) and ursolic acid (UA) strongly inhibited CYP3A4 activity while UA and lupeol moderately inhibited CYP2C19. All extracts exhibited strong activity against the tested isozymes at 50-100 µg/ml. BA and all plant extracts blocked the formation of major diazepam metabolites. CONCLUSIONS: Betulinic acid, UA and both the extracts and blended product are expected to affect the metabolism of diazepam when given in high dose.


Asunto(s)
Ansiolíticos/farmacología , Sistema Enzimático del Citocromo P-450/metabolismo , Diazepam/farmacología , Extractos Vegetales/farmacología , Cromatografía Líquida de Alta Presión/métodos , Humanos , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Triterpenos Pentacíclicos/farmacología , Hojas de la Planta/química , Triterpenos/farmacología , Ácido Betulínico , Ácido Ursólico
8.
Pharm Biol ; 56(1): 485-494, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30303034

RESUMEN

CONTEXT: Plants of the genus Echinacea (Asteraceae) are among the most popular herbal supplements on the market today. Recent studies indicate there are potential new applications and emerging markets for this natural health product (NHP). OBJECTIVE: This review aims to synthesize recent developments in Echinacea biotechnology and to identify promising applications for these advances in the industry. METHODS: A comprehensive survey of peer-reviewed publications was carried out, focusing on Echinacea biotechnology and impacts on phytochemistry. This article primarily covers research findings since 2007 and builds on earlier reviews on the biotechnology of Echinacea. RESULTS: Bioreactors, genetic engineering and controlled biotic or abiotic elicitation have the potential to significantly improve the yield, consistency and overall quality of Echinacea products. Using these technologies, a variety of new applications for Echinacea can be realized, such as the use of seed oil and antimicrobial and immune boosting feed additives for livestock. CONCLUSIONS: New applications can take advantage of the well-established popularity of Echinacea as a NHP. Echinacea presents a myriad of potential health benefits, including anti-inflammatory, anxiolytic and antibiotic activities that have yet to be fully translated into new applications. The distinct chemistry and bioactivity of different Echinacea species and organs, moreover, can lead to interesting and diverse commercial opportunities.


Asunto(s)
Biotecnología/tendencias , Echinacea , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/uso terapéutico , Transferencia de Tecnología , Animales , Antiinflamatorios/aislamiento & purificación , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Biotecnología/métodos , Predicción , Humanos , Inflamación/tratamiento farmacológico , Fitoquímicos/aislamiento & purificación , Fitoquímicos/farmacología , Fitoquímicos/uso terapéutico , Extractos Vegetales/farmacología
9.
J Ethnopharmacol ; 216: 63-70, 2018 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-29414121

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The Maya have traditionally used copal, Protium copal, as incense during ceremonies since pre-Columbian times. Anecdotally, copal (when burned as incense), is thought to elicit mentally uplifting and calming effects. The main objective of this study was to determine whether the incense elicits anxiolytic-like behavior in animal models using rats. A second objective was to characterize active constituents and discern potential mechanism(s) of action, specifically the involvement of the GABAergic and endocannabinoid (eCB) systems. Despite the extensive Central American use of this resin, there are currently no known scientific behavioral or pharmacological studies done with the incense. MATERIALS AND METHODS: Quantification of the triterpenes in the copal resin and cold trapped incense was achieved by HPLC MS. Behavioral effects in rats were assessed using the elevated plus maze (EPM), social interaction (SI) test, conditioned emotion response (CER) and Novel object recognition (NOR) paradigms. Rats were exposed to burning copal (200 mg) over 5 min in a smoking chamber apparatus and then immediately tested in each behavioral paradigm. Follow-up SI tests were done using two antagonists flumazenil (1 mg/kg) and AM251 (1 mg/kg) administered systemically. Inhibition of MAGL (monoacylglycerol lipase) was measured by microplate assay with recombinant human enzyme and probe substrate. RESULTS: Phytochemical analysis revealed that copal resin and incense had high α- and ß-amyrins and low lupeol triterpene content. Exposure to Protium copal incense significantly reduced anxiety-like behavior in the SI and CER tests. In contrast, no anxiolytic effects were observed in the EPM. The CER effect was time dependent. Both flumazenil and AM251 blocked the anxiolytic activity of copal revealing the involvement of GABAergic and endocannabinoid systems. Copal, as well as the identified triterpenes, potently inhibited monoacylglycerol lipase (MAGL) activity in vitro (IC50 ≤ 811 ng/mL). CONCLUSIONS: This is the first study to show that copal incense from Protium copal elicits anxiolytic-like effects in fear and social interaction models as evidenced by a reduced learned fear behavior and an increase in active social interaction. It's high α and ß-amyrin content suggests behavioral effects may be mediated, in part, by the known action of these terpenes at the benzodiazepine receptor. Furthermore, P. copal's observed activity through the eCB system via MAGL offers a new potential mechanism underlying the anxiolytic activity.


Asunto(s)
Ansiolíticos/farmacología , Ansiedad/prevención & control , Conducta Animal/efectos de los fármacos , Burseraceae , Conducta Ceremonial , Extractos Vegetales/farmacología , Resinas de Plantas/farmacología , Animales , Ansiolíticos/aislamiento & purificación , Ansiedad/metabolismo , Ansiedad/psicología , Burseraceae/química , Proteínas Portadoras/efectos de los fármacos , Proteínas Portadoras/metabolismo , Modelos Animales de Enfermedad , Endocannabinoides/metabolismo , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/farmacología , Conducta Exploratoria/efectos de los fármacos , Miedo/efectos de los fármacos , Flumazenil/farmacología , Humanos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Monoacilglicerol Lipasas/antagonistas & inhibidores , Monoacilglicerol Lipasas/metabolismo , Fitoterapia , Piperidinas/farmacología , Extractos Vegetales/aislamiento & purificación , Plantas Medicinales , Pirazoles/farmacología , Ratas Sprague-Dawley , Receptor Cannabinoide CB1/efectos de los fármacos , Receptor Cannabinoide CB1/metabolismo , Receptores de GABA-A/efectos de los fármacos , Receptores de GABA-A/metabolismo , Resinas de Plantas/química , Transducción de Señal/efectos de los fármacos , Conducta Social
10.
Diabetologia ; 61(4): 919-931, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29270816

RESUMEN

AIMS/HYPOTHESIS: There is growing evidence that fruit polyphenols exert beneficial effects on the metabolic syndrome, but the underlying mechanisms remain poorly understood. In the present study, we aimed to analyse the effects of polyphenolic extracts from five types of Arctic berries in a model of diet-induced obesity. METHODS: Male C57BL/6 J mice were fed a high-fat/high-sucrose (HFHS) diet and orally treated with extracts of bog blueberry (BBE), cloudberry (CLE), crowberry (CRE), alpine bearberry (ABE), lingonberry (LGE) or vehicle (HFHS) for 8 weeks. An additional group of standard-chow-fed, vehicle-treated mice was included as a reference control for diet-induced obesity. OGTTs and insulin tolerance tests were conducted, and both plasma insulin and C-peptide were assessed throughout the OGTT. Quantitative PCR, western blot analysis and ELISAs were used to assess enterohepatic immunometabolic features. Faecal DNA was extracted and 16S rRNA gene-based analysis was used to profile the gut microbiota. RESULTS: Treatment with CLE, ABE and LGE, but not with BBE or CRE, prevented both fasting hyperinsulinaemia (mean ± SEM [pmol/l]: chow 67.2 ± 12.3, HFHS 153.9 ± 19.3, BBE 114.4 ± 14.3, CLE 82.5 ± 13.0, CRE 152.3 ± 24.4, ABE 90.6 ± 18.0, LGE 95.4 ± 10.5) and postprandial hyperinsulinaemia (mean ± SEM AUC [pmol/l × min]: chow 14.3 ± 1.4, HFHS 31.4 ± 3.1, BBE 27.2 ± 4.0, CLE 17.7 ± 2.2, CRE 32.6 ± 6.3, ABE 22.7 ± 18.0, LGE 23.9 ± 2.5). None of the berry extracts affected C-peptide levels or body weight gain. Levels of hepatic serine phosphorylated Akt were 1.6-, 1.5- and 1.2-fold higher with CLE, ABE and LGE treatment, respectively, and hepatic carcinoembryonic antigen-related cell adhesion molecule (CEACAM)-1 tyrosine phosphorylation was 0.6-, 0.7- and 0.9-fold increased in these mice vs vehicle-treated, HFHS-fed mice. These changes were associated with reduced liver triacylglycerol deposition, lower circulating endotoxins, alleviated hepatic and intestinal inflammation, and major gut microbial alterations (e.g. bloom of Akkermansia muciniphila, Turicibacter and Oscillibacter) in CLE-, ABE- and LGE-treated mice. CONCLUSIONS/INTERPRETATION: Our findings reveal novel mechanisms by which polyphenolic extracts from ABE, LGE and especially CLE target the gut-liver axis to protect diet-induced obese mice against metabolic endotoxaemia, insulin resistance and hepatic steatosis, which importantly improves hepatic insulin clearance. These results support the potential benefits of these Arctic berries and their integration into health programmes to help attenuate obesity-related chronic inflammation and metabolic disorders. DATA AVAILABILITY: All raw sequences have been deposited in the public European Nucleotide Archive server under accession number PRJEB19783 ( https://www.ebi.ac.uk/ena/data/view/PRJEB19783 ).


Asunto(s)
Hígado Graso/tratamiento farmacológico , Hígado Graso/metabolismo , Resistencia a la Insulina , Intestinos/efectos de los fármacos , Hígado/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Péptido C/sangre , Dieta Alta en Grasa , Endotoxemia/metabolismo , Frutas/química , Glucosa/metabolismo , Homeostasis , Insulina/sangre , Insulina/metabolismo , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Obesidad/metabolismo , ARN Ribosómico 16S/genética , Factores de Tiempo
11.
J Ethnopharmacol ; 194: 651-657, 2016 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-27773798

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Larix laricina, a native tree of North America, is a highly respected medicinal plant used for generations by Indigenous Peoples across its range, including the Cree of northern Québec who use the bark to treat symptoms of diabetes. This study investigates the antioxidant capacity and bioavailability of active constituents identified in L. laricina bark extracts. MATERIALS AND METHODS: (1) Oxygen radical absorbance capacity (ORAC) assay was employed to test antioxidant capacity of organic extracts (80% ethanol) from bark of L. laricina as well as fractions, isolated compounds, and media samples collected during permeability assays. (2) Caco-2 cell monolayer cultures were used to determine the permeability of identified antioxidants, which were quantified in basolateral media samples using liquid chromatography - tandem mass spectrometry (HPLC-ESI-MS/MS). RESULTS: Crude ethanolic extract possessed strong antioxidant potential in vitro (7.1±0.3 Trolox equivalents (TE) µM/mg). Among the 16 L. laricina fractions obtained by chromatographic separation, fraction 10 (F10) showed the highest antioxidant capacity (21.8±1.7µm TE/mg). Among other identified antioxidants, the stilbene rhaponticin (isolated from F10) was the most potent (24.6±1.1µm TE/mg). Caco-2 transport studies revealed that none of the identified compounds were detectable in basolateral samples after 2-h treatment with crude extract. In monolayers treated with F10 (60% rhaponticin), small quantities of rhaponticin were increasingly detected over time in basolateral samples with an apparent permeability coefficient (Papp) of 1.86×10-8cm/s (0-60min). To model potential effects on blood redox status, we evaluated the antioxidant capacity of collected basolateral samples and observed enhanced activity over time after exposure to both extract and F10 (75µg/mL) relative to control. CONCLUSIONS: By profiling the antioxidant constituents of L. laricina bark, we identified rhaponticin as the most potent oxygen radical scavenger and observed low permeability in Caco-2 cell monolayers but an increase in basolateral antioxidant capacity.


Asunto(s)
Larix/química , Medicina Tradicional , Corteza de la Planta/química , Células CACO-2 , Cromatografía Líquida de Alta Presión , Humanos , Indígenas Norteamericanos , Espectrometría de Masa por Ionización de Electrospray
12.
PLoS One ; 10(11): e0142804, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26606749

RESUMEN

BACKGROUND: Physicians around the world report to using placebos in a variety of situations and with varying degrees of frequency. Inconsistent methodologies, however, complicate interpretation and prevent direct comparisons across studies. While US- and Canada-based physicians share similar professional standards, Canada harbours a less-litigious universal healthcare model with no formal placebo-related policy-factors that may impact how physicians view and use placebos. METHODS: To compare American and Canadian data, we circulated an online survey to academic physicians practicing in Canada, collected anonymous responses, and extracted those of internists and rheumatologists for comparison to US data obtained through parallel methodologies. RESULTS: Whereas our data show overall concordance across the border-from definitions to ethical limitations and therapeutic potential-differences between American- and Canadian-based placebo practices merit acknowledgement. For example, compared to 45%-80% among US-based respondents, only 23±7% of Canada-based respondents reported using placebos in clinical practice. However, 79±7% of Canada-respondents-a figure comparable to US data-professed to prescribing at least one form of treatment without proven or expected efficacy. Placebo interventions including unwarranted vitamins and herbal supplements (impure placebos) as well as sugar pills and saline injections (pure placebos) appear more common in Canada, where more doctors described placebos as "placebos" (rather than "medications") and used them as a "diagnostic" tool (rather than a means of placating patient demands for treatment). INTERPRETATION: Cross-border variation in the use of clinical placebos appears minor despite substantial differences in health care delivery system, malpractice climate, and placebo-related policy. The prevalence of impure placebos in both Canadian and US clinics raises ethical and practical questions currently unaddressed by policy and warranting investigation.


Asunto(s)
Prescripciones de Medicamentos/estadística & datos numéricos , Médicos/ética , Placebos/uso terapéutico , Pautas de la Práctica en Medicina/estadística & datos numéricos , Actitud del Personal de Salud , Canadá , Femenino , Humanos , Masculino , Persona de Mediana Edad , Preparaciones de Plantas/uso terapéutico , Pautas de la Práctica en Medicina/ética , Encuestas y Cuestionarios , Estados Unidos , Vitaminas/uso terapéutico
14.
Plant Foods Hum Nutr ; 69(1): 71-7, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24448675

RESUMEN

Evidence supports the health promoting benefits of berries, particularly with regard to the prevention and management of chronic diseases such cardio- and cerebrovascular disease, diabetes and Alzheimer's disease. Two related pathophysiological features common to many of these conditions are oxidative stress and the accumulation of advanced glycation endproducts (AGEs). Whereas antioxidant properties are well-established in several species of berries and are believed central to their protective mechanisms, few studies have investigated the effects of berries on AGE formation. Here, employing a series of complementary in vitro assays, we evaluated a collection of wild berry extracts for 1) inhibitory effects on fluorescent-AGE and Nε- (carboxymethyl)lysine-albumin adduct formation, 2) radical scavenging activity and 3) total phenolic and anthocyanin content. All samples reduced AGE formation in a concentration-dependent manner that correlated positively with each extract's total phenolic content and, to a lesser degree, total anthocyanin content. Inhibition of AGE formation was similarly related to radical scavenging activities. Adding antiglycation activity to the list of established functional properties ascribed to berries and their phenolic metabolites, our data provide further insight into the active compounds and protective mechanisms through which berry consumption may aid in the prevention and treatment of chronic diseases associated with AGE accumulation and toxicity. As widely available, safe and nutritious foods, berries represent a promising dietary intervention worthy of further investigation.


Asunto(s)
Antocianinas/farmacología , Antioxidantes/farmacología , Dieta , Frutas/química , Productos Finales de Glicación Avanzada/metabolismo , Fenoles/farmacología , Extractos Vegetales/farmacología , Relación Dosis-Respuesta a Droga , Depuradores de Radicales Libres/farmacología , Alimentos Funcionales , Humanos , Plantas Comestibles/química
15.
BMC Complement Altern Med ; 12: 245, 2012 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-23216659

RESUMEN

BACKGROUND: The purple pitcher plant, Sarracenia purpurea L., is a widely distributed species in North America with a history of use as both a marketed pain therapy and a traditional medicine in many aboriginal communities. Among the Cree of Eeyou Istchee in northern Québec, the plant is employed to treat symptoms of diabetes and the leaf extract demonstrates multiple anti-diabetic activities including cytoprotection in an in vitro model of diabetic neuropathy. The current study aimed to further investigate this activity by identifying the plant parts and secondary metabolites that contribute to these cytoprotective effects. METHODS: Ethanolic extracts of S. purpurea leaves and roots were separately administered to PC12 cells exposed to glucose toxicity with subsequent assessment by two cell viability assays. Assay-guided fractionation of the active extract and fractions was then conducted to identify active principles. Using high pressure liquid chromatography together with mass spectrometry, the presence of identified actives in both leaf and root extracts were determined. RESULTS: The leaf extract, but not that of the root, prevented glucose-mediated cell loss in a concentration-dependent manner. Several fractions elicited protective effects, indicative of multiple active metabolites, and, following subfractionation of the polar fraction, hyperoside (quercetin-3-O-galactoside) and morroniside were isolated as active constituents. Phytochemical analysis confirmed the presence of hyperoside in the leaf but not root extract and, although morroniside was detected in both organs, its concentration was seven times higher in the leaf. CONCLUSION: Our results not only support further study into the therapeutic potential and safety of S. purpurea as an alternative and complementary treatment for diabetic complications associated with glucose toxicity but also identify active principles that can be used for purposes of standardization and quality control.


Asunto(s)
Citoprotección/efectos de los fármacos , Glucosa/toxicidad , Extractos Vegetales/química , Plantas Medicinales/química , Sustancias Protectoras/química , Sarraceniaceae/química , Animales , Células PC12 , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Hojas de la Planta/química , Sustancias Protectoras/aislamiento & purificación , Sustancias Protectoras/farmacología , Ratas
16.
Planta Med ; 77(2): 196-204, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20717877

RESUMEN

Nonenzymatic formation of advanced glycation end products (AGEs) is accelerated under hyperglycemic conditions characteristic of type 2 diabetes mellitus and contributes to the development of vascular complications. As such, inhibition of AGE formation represents a potential therapeutic target for the prevention and treatment of diabetic complications. In the present study, ethanolic extracts of 17 medicinal plants were assessed for inhibitory effects on in vitro AGE formation through fluorometric and immunochemical detection of fluorescent AGEs and N(ε)-(carboxymethyl)lysine adducts of albumin (CML-BSA), respectively. Most extracts inhibited fluorescent AGE formation with IC (50) values ranging from 0.4 to 38.6 µg/mL and all extracts reduced CML-BSA formation but to differing degrees. Results obtained through both methods were highly correlated. Antiglycation activities were positively correlated with total phenolic content, free radical scavenging activity and reduction in malonyldiadehyde levels following oxidation of low-density lipoprotein, but negatively correlated with lag time to formation of conjugated dienes. Together, these results provide evidence that antioxidant phenolic metabolites mediate the antiglycation activity of our medicinal plant collection, a relationship that likely extends to other medicinal and food plants.


Asunto(s)
Antioxidantes/farmacología , Productos Finales de Glicación Avanzada/antagonistas & inhibidores , Fenoles/farmacología , Extractos Vegetales/farmacología , Plantas Medicinales/química , Canadá , Depuradores de Radicales Libres/química , Productos Finales de Glicación Avanzada/química , Productos Finales de Glicación Avanzada/metabolismo , Lisina/análogos & derivados , Lisina/antagonistas & inhibidores , Lisina/química , Malondialdehído/química , Oxidación-Reducción , Extractos Vegetales/química , Factores de Tiempo
17.
Planta Med ; 76(13): 1439-46, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20301057

RESUMEN

Obesity is an epidemic in most developed countries and novel therapeutic approaches are needed. In the course of a screening project of medicinal plants used by the Eastern James Bay Cree of Canada and having potential for the treatment of diabetes, we have identified several products that inhibit adipogenesis, suggesting potential antiobesity activities. The inhibitory activity of two of these, the extract of the inner bark of the deciduous trees Alnus incana ssp. rugosa (Speckled Alder) and Populus balsamifera L. (Balsam Poplar), was analyzed using the 3T3-L1 cell model of adipogenesis. Intracellular triglyceride accumulation, pre-adipocyte proliferation, and PPAR- γ activity were measured. Alnus incana extracts acted early in the differentiation process but did not affect clonal expansion of pre-adipocytes nor the morphological transformation from fibroblast-like to rounded fat-laden cells. Alnus incana extracts were found to act as partial agonists toward PPAR- γ activity. In contrast, Populus balsamifera extracts completely abrogated adipogenesis, severely limited clonal expansion of pre-adipocytes and generally maintained cells in an undifferentiated fibroblast-like morphology. Populus balsamifera extracts exerted antagonistic action against PPAR- γ activity. It is concluded that, through their actions on the adipocyte, these plant products may be useful for the treatment of obesity and related metabolic diseases.


Asunto(s)
Adipocitos/efectos de los fármacos , Adipogénesis/efectos de los fármacos , Alnus , Fármacos Antiobesidad/farmacología , Obesidad/prevención & control , Extractos Vegetales/farmacología , Populus , Células 3T3-L1 , Adipocitos/metabolismo , Animales , Fármacos Antiobesidad/uso terapéutico , Proliferación Celular/efectos de los fármacos , Fibroblastos , Ratones , Obesidad/metabolismo , PPAR gamma/metabolismo , Corteza de la Planta , Extractos Vegetales/uso terapéutico , Triglicéridos/metabolismo
18.
Planta Med ; 76(14): 1519-24, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20301058

RESUMEN

Among modern day metabolic diseases, obesity has reached epidemic proportions worldwide and novel therapeutic support strategies are urgently needed. Adipocytes are interesting targets in this context. Using ethnobotanical and bioassay screening techniques, we have identified two Boreal Forest plants used by the James Bay Cree that potently inhibit adipogenesis, namely ALNUS INCANA ssp. RUGOSA (Speckled Alder) and POPULUS BALSAMIFERA (Balsam Poplar). The mode of action of this inhibitory activity was reported in a companion paper. The current study report the results of a classical bioassay-guided fractionation approach aimed at identifying the active principles responsible for the inhibition of adipogenesis, as measured using triglyceride accumulation in the 3T3-L1 adipocyte model cell line. The glycosides oregonin and salicortin were isolated and identified as the respective active principles for ALNUS INCANA and POPULUS BALSAMIFERA. These compounds thus offer promise as novel agents to mitigate the incidence or the progression of obesity.


Asunto(s)
Adipogénesis/efectos de los fármacos , Alnus/química , Diarilheptanoides/farmacología , Glucósidos/farmacología , Corteza de la Planta/química , Populus/química , Células 3T3 , Animales , Bioensayo , Fraccionamiento Químico , Diarilheptanoides/química , Diarilheptanoides/aislamiento & purificación , Glucósidos/química , Glucósidos/aislamiento & purificación , Ratones , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología
19.
Phytochem Anal ; 21(4): 328-39, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20135709

RESUMEN

INTRODUCTION: Ericaceae medicinal plants are traditionally used by the Eeyou Istchee Cree and other northern peoples of North America to treat type 2 diabetic symptoms. Because of the importance of phenolics as potential cures for degenerative diseases including type 2 diabetes, an analytical method was developed to detect them in the leaf extracts of 14 Ericaceae plants. OBJECTIVE: To develop an optimised method which is applicable to a relatively large number of Ericaceae plants using their leaf extracts. For this purpose phenolics with a wide range of polarity, including a glucosylated benzoquinone, two phenolic acids, three flavanols, a flavanone, a flavone and five flavonols, were included in this study. METHODOLOGY: Characterisation of phytochemicals in extracts was undertaken by automated matching to the UV spectra to those of an in house library of plant secondary metabolites and the authentication of their identity was achieved by reversed phase-high-performance chromatography-diode array detection-atmospheric pressure chemical ionisation/mass selective detection. RESULTS: Twenty-six phenolics were characterised within 26 min of chromatographic separation in 80% ethanol extracts of 14 Ericaceae plants. The calibration curves were linear within 0.5-880 microg/g dry mass of the plant with regression values better than 0.995. The limits of detection ranged from 0.3 for microg/mL for (+)-catechin to 2.6 microg/mL for chlorogenic acid. This is a first study dealing with relatively large number of Ericaceae extracts and is applicable to other plants of same family.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Ericaceae/química , Indígenas Norteamericanos , Plantas Medicinales/química , Humanos , Límite de Detección
20.
Phytother Res ; 24(5): 741-7, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-19927274

RESUMEN

Like many aboriginal populations, First Nations communities such as the Cree of Eeyou Istchee are facing continuously increasing rates of diabetes and related complications. Advanced glycation endproducts (AGEs), which readily form and accumulate with sustained hyperglycemia, contribute to the development of diabetic complications and, as such, are considered a potential therapeutic target. In the present study, the inhibition of AGE formation by ethanolic extracts of the Cree medicinal plant Vaccinium vitis-idaea L. was assessed by fluorometric detection of fluorescent AGEs and immunodetection of N(epsilon)-(carboxymethyl)lysine adducts of albumin. Extracts from V. vitis-idaea berries demonstrated a concentration-dependent inhibition of AGE formation in both measures. High performance liquid chromatography mass spectrometry (HPLC/MS) identified nine main phenolic constituents. Four were selected for further testing, of which catechin, quercetin-3-O-galactoside and cyanidin-3-O-glucoside but not para-coumaric acid displayed antiglycation activities. These results demonstrate that the flavonoid components of the berry extract are potent antiglycation agents and provide pharmacological validation for the traditional use of V. vitis-idaea as an antidiabetic remedy.


Asunto(s)
Flavonoides/química , Productos Finales de Glicación Avanzada/química , Fenoles/química , Extractos Vegetales/química , Vaccinium vitis-Idaea/química , Cromatografía Líquida de Alta Presión , Flavonoides/aislamiento & purificación , Frutas/química , Lisina/análogos & derivados , Medicina Tradicional , Fenoles/aislamiento & purificación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA